Safety system for electric elevators



June 5', 1928; I 1,672,675

- C. C. CLYMER SAFETY SYSTEM FOR ELECTRIC ELEVATORS Fil'ed Dec. 15, 1926Whom Invenbom Charles C.Cl5mer-;

y M Z His Attorney:

, Patented June 5, 1928.

. UNITED STATES PATENT onion. 1

cmLEsc. (mutant, of SCHENECTADY, NE YORK, assIenoB T0 GENERA ELECTRIC,

, COMPANY, a CORPORATION on NEW .YORK. 7

, sArnrY SYSTEM FOR nLnc'rRionLEvArons.

Application filed De em er 15, 1336. Serial No. 155,062.

My-invention is directed to improvements in safety systemsfor electricelevators for the prevention of accidents due to improper manipulationof an elevator controller in 8 connection with the closing of theelevator door or gate.

'Sys t ems have heretofore been provided whereby the elevator motorcannot be energized to effect operation of the elevator in 10casethe-elevator door or gate is in its open positiomit beingnecessarythat all of the gate contacts be closed before the controlleris operated to efi'ect operation. of the elevator motor. Systems havealso been hereto- 16 fore provided whereby in case the elevatorcontroller is first moved to an operative position 'andfthe gatecontacts are afterwards closed by the closing of an elevator door orgateQthe elevator motor cannot be energized 20 until after thecontroller is returned to its oil or neutral position. Such formersystems 'have left'much to be desired in the direction of simplicity ofconstruction and arrangementyand in the reliabilityof-the operationthereof. 5 i 1.

\ The objects of my inventionis to provide animproved system havingfeatures of simplicity of construction and arrangemenfiand reliabilityof operation for taking careof the above condition, among others;

"In carrying my invention into effect in the form which I now regard asthe preferred form thereof, I provide a relay which has its Windingconnected in multiple relation wit-h the winding or windings of theelectroresponsive switch mechanism which effects the connection of anelevator motorto its source of supply for the desired direction'ofoperation, and connect this multiple circuit in series relation with aresistor connected in the circuit of the gate contacts. The arrangementis suchthat in case the elevator controller is first moved to anoperative posi.

the resistor will prevent operation of the electro'responsive motorcontrolling mechanism to connect the motor to its source of supply, andalso prevent'operation of the relay by limiting the current through thewindings ofthe switch mechanism and the 'tion and the gate contacts arethen closed,

relay.'- That will necessitate that the controller'be returned to itsoff- 01' neutral position, thereby opening one of the multiple paths sothat the windingof the relay is now connected in series relation withthe resistor and the gate contacts, and this relay will then besufliciently energized'to 0perate and shunt the resistor. If theelevator controller is then moved from its neutral position to anoperative position, the windings of the electroresponsive motorcontrolling mechanism will be sulficiently energized to efi'ectop'eration thereof. It the gate contacts are all first closedwith themotor controller in its neutral position, therelay will operate to shuntthe resistor and thus permit operation of the electroresponsive motorcontrolling switch mechanism when the controller is subsequentlyoperated to an operative position.

Among the advantages of my invention are the following: The scheme isvery simple and readily understood by electricians whose duty it is toinstall and keep electric elevator equipment in operation. The sysl6 temis'readily adaptable to existingsystems which either do not haveprotective arrangements for preventing improper operation of an elevatorcontroller, or for taking the place of apparatus in morecomplicatedsystems intended to take 'care of the general conditions outlined above;Another advantage'of the invention is that in'case for any reason thegoverning relay either sticks in its closed position, or thewinding'thereof is burned out and the relay does not close, a certainmeasur'e'of protection is nevertheless had since the motor controller isinoperative to effect operation oif the elevator until after the gatecontacts have been closed.

In the accompanying drawing I have shown a very simplified system ofmotor controlfor an electrified elevator, hoist or the likefwherein myinvention is incorporated as one of the elements thereof.

1 Referring to" the drawing, the elevator cage 10 is, arranged to beoperated "in the switch 13-which governs the eleotrorespon-v sive motorcontrolling switch mechanism indicated as the directional or reversingcontactors 14 and 15. The safety relay 16, together with the. resistor1.7v controlled thereby, are provided for insuring that the'controller13 must be in its neutral position, as indicated, and the gate contacts18 all closed beforeeitherr contactor' 14H'or15' can 'b efener' gized toefi'ect operation ofm'otor 'll'it'or' either It will y direction ofoperation otthe elevator. be observed that the winding ofrelay" 16 isconnected in multiple relation with the windings of either the contactor14 or contactor 1 5'- loy:= the: operation of controller 13. It

will: also be; observed that this multiple circuit is: included inseries relation with the resistor lZiand thegate-contacts '18. When therelay 16 .operates, ,itshunts-.theresistor w-AS thus constructed andarranged, .and

with th eeparts in their respective positions indioa tedwin thedrawing,-the operation of my invention isas follows: Assume that itisdesi-red to. operateithe elevatorin up directiom: Thelower gatecontact 18. will first beclosed by first closingrthe elevator door orgate, and thisiwill connect the winding ofthe-relay 16 acrossthe supplycircuit .19 in series relation with theresistor 17. The value of thisresistor is such that with the; controller 13 a in its neutral position,sufficient current: will flow through the wind ing of relay 16 to effectoperation of the relay. andz the; consequent shuntings offlthe resistor17; It, now, the manually operated controller 13 is moved to its firstclockwise positiomthe. directional-' contactor will bevenergizedutoclose and 1 connect thermotor armature to the source of:supply through the;contacts ofthiscontactor and thestartin'g; resistor20. This isgthe vproper sequence of: operation ofthe parts in-orden toefiect operation of the elevator, It,v instead of that-proper operation,thecontroller 18 is firstwmoved to an, operative position, before thelowergate contact 18,. is closed, neither the winding; ,of directionalcontactor 15 ,nor; the winding-of relay 16 will receive sufficient;venergization to effect operation of these, devices. That is because of,the fact that: tl'1e-,Wil'lCllIlgi Of contactornle and the windingofrelay;v 16 v are connected to. the same conductor ofthe source ofsupply, and when thelowen' gate contact 18 is closed,

thesetwo windings will be in. multiple rela tioniwith each other and.the multiple cir- C'LlltdSvlIlseries, relation with. the resistor 17 andthe gatecontacts 18.v Under these conditions, the.resistor 17 willprevent sufficient energization of contaotor 15 and relay 16 for:operation thereof Ifthe con- ;troller.13 isreturned to its neutralposition I is the circuit; through the winding of contactor l5 is openand the winding of relay 16 is now sufficient-1y energized to eii ectthe closing of the relay and the shunting of the resistor 17 so thatwhen the controller is ]ing -switch mechanism, and gate contacts forinsuring that the elevator cannot start until after the gate contactshave been closed. Itlwill, also be observed that the system is readilyapplicable for the replacement of more :complicated and less, reliable'systems previously installed for accomplishingthe general purpose. Afurther feature-is that in caselany gate or door contactsareopened afterthe elevator isv in operationptherelay 16 and, the selected directionalc ontafctor will be-immediately opened'andth e elevator stopped. If, therelay- 16 isv closed, tlie,controllerv 13 being in its neutral position,1 and anygate or door contacts are opened, the relaywill immediately"open, thnsi prevent- .ing; ,unsate operation. q

, hat I claimas new and desire to securetby Letters Patent of theflliiited States In combination in safety, system for the control ofelectric elevators, electroresponsive. reversing switch mechanism forcontrolling the direction of operation ofthe elevator, a reversingmanual controller for controlling i said switch mechanism, a safetyelectromagnetic relay, a resistor, gate. contacts, and electr calconnections between said. controller, the. operatingwindingsof said.switch mechanism, the winding oflsaid relay, 2 and said resistor wherebythe resistor prevents sufficient energization of said, reversingr switchm'echanisnr for operation thereof in case said gate: contacts lareclosed vatoroperative position, therebynecessitating the return oi saidcontroller to a neutral position to effect suflicient energization ofsaid relay to shunt said resistor and per- .mit sufl'icient energizationof said switch mechanism for operation thereof when said elevatoroperative position witli the said gate contacts Imaintained: closed, I

2. In combination in a safety system for electric. elevators, anelectric motor: for operating are. elevator, electromagnetic switchmechanlsm 'for controlling the connection after said; controller isoperatedtoaanv elecontroller is subsequently operated. to an gatecontacts in series relation across said source of supply, the operatingwinding of said switch mechanism being connected to be included inmultiple relation with the Winding of said relay when said controller isin an operative position, whereby in case said gate contacts are closedafter said controller is operated to an operative position, saidresistor prevents sufiicient energization of said switch mechanism andsaid relay for operation thereof, thereby necessitating the return ofsaid controller to a neutral position to permit said relay to shunt saidresistor.

In witness whereof I have hereunto set my hand this 14th day ofDecember, 1926.

' CHARLES c. CLYMER.

